1. Field of the Invention
This invention lies in the field of smokeless combustion of waste gases in flare stacks.
More particularly it concerns apparatus for the rapid control of the flow of smoke suppressant to the stack upon the initiation of a rapid flow of waste gas to the stack.
2. Description of the Prior Art
In the prior art of flare burning of emergency released combustible gases to flares, it is a common procedure to supply and inject steam to the flare flame, for suppression of smoke.
It will be obvious from the study of the prior art, that both flared gases and steam, as a suppressant, must be delivered to the flare simultaneously, for gas burning and steam delivery to chemically accomplish the suppression of smoke, in the combustion of the gases. In order to accomplish the simultaneous gas and steam delivery to the flare on a controlled basis, there have been systems devised wherein detector means of various sorts, initiate a pneumatic control fluid to a controlled valve, so that the valve can be opened to initiate flow of steam, etc.
These systems have been widely used but have exhibited the undersirable characteristic of delayed steam delivery, and consequent considerable smoke production, when sudden bursts of gas flow, equal to a substantial portion of flare ultimate capacity, arrive at the flare discharge point. This sudden flow of gas is ignited and burned before steam, as a smoke suppressant, can be delivered to the flare. The delay in steam delivery is due to either the basic principle of operation, or to the slow response of the control system, which is characteristic of pneumatic control, generally, or to both, as the case may be. It is therefore important to find some way to quickly detect the onset of gas flow to the flare, and equally quickly to initiate the flow of steam, neither of which is provided by the prior art equipment.